Golf ball

ABSTRACT

This invention relates to an electronic golf ball comprising a central resilient sphere, a mass of elastic material surrounding the sphere and an outer casing, the central sphere including an electric squegging oscillator circuit, a battery therefor and a transmitting coil, all enclosed in a spherical mass of a set resin which forms a solid core, the spherical mass being located with close fit in a hollow spherical cavity formed in the central resilient sphere. The battery is a mercury cell located within the transmitting coil, as are the other components of the squegging oscillator circuit. The electrical circuit may include components which permit the oscillator to be turned on and off when the golf ball is brought into and then moved out of an A.C. magnetic field having a predetermined frequency.

Horchler Jan. 1,1974

[ GOLF BALL [75] Inventor: Stephen Alexander Horchler,

Eskbank, Scotland [73] Assignee: Euronics Limited, Edinburgh,

Scotland 22 Filed: Dec. 2, 1971 21 Appl. No.: 204,109

OTHER PUBLICATIONS Radio-Electronics, June 1956, page 79 273-213 (NPNTRANSISTOR (miner-roe f, I

r (RESISTOR) Primary Examiner-George .l. Marlo Att0rneyMichael S.Striker [5 7] ABSTRACT This invention relates to an electronic golf ballcomprising a central resilient sphere, a mass of elastic materialsurrounding the sphere and an outer casing, the central sphere includingan electric squegging oscillator circuit, a battery therefor and atransmitting coil, all enclosed in a spherical mass of a set resin whichforms a solid core, the spherical mass being located with close fit in ahollow spherical cavity formed in the central resilient sphere. Thebattery is a mercury cell located within the transmitting coil, as arethe other components of the squegging oscillator circuit. The electricalcircuit may include components which permit the oscillator to be turnedon and off when the golf ball is brought into and then moved out of anA.C. magnetic field having a predetermined frequency.

9 Claims, 5 Drawing Figures Pmmmm 1 m4 3,782,730 SHEET 16F 2 (NPNTRANSISTOR LCI'RANQMITTING eon.)

C2(0APAclTOR) (Msrzcuzv CELL) GOLF BALL This invention relates to a golfball containing an electric oscillator circuit which assists in therecovery of golf balls lost during a game of golf. It is a well knownfact that many golf balls are lost due to the fact that during, play thegolf ball lands in a particularly overgrown area of the golf course. Theloss can occur even though the'ball may have been visible during itsentire flight and the approximate region of the landing of the ball isknown. The loss of a golf ball not only entails financial loss to theplayer it also means that the player is put at a disadvantage as far asthat game is concerned. The present invention reduces the occurrence oflost golf balls and players employing golf balls which can be recoveredare at an advantage both financially and by not losing unnecessarypoints over lost balls.

According to one aspect of the invention of golf ball comprises acentral resilient sphere, a mass of elastic material surrounding thesphere and an outer casing, in which the sphere includes an electricoscillator circuit and a battery therefor, and is characterized in thatthe oscillator circuit, a transmitting coil and the battery are enclosedin a spherical mass of a set resin to form a solid core, the sphericalmass being located with close fit in a hollow spherical cavity formed inthe central resilient sphere.

Conveniently the oscillator circuit is tuned to a particular frequencyand generates an induction field at that frequency, the oscillatorycircuit squegging so that its output comprises bursts of oscillation atthe desired frequency interspersed by longer periods of nonoscillation.The duty ratio (i.e. the ratio between the periods of non-oscillation(off periods) and the periods of oscillation (on periods)) can be chosenat will, but is preferably within the range 100:1 to 1,00011. The burstsof oscillation can be kept stable and the repetition of these burstsappear in a detector unit (which may be a' simple radio receiver tunedto the frequency of the oscillator circuit) as a modulation frequencycharacteristic of the oscillator circuit employed. By filtering thispulse repetition frequency the detector unit can respond to differentfrequencies making identification of different golf balls possible.

A suitable frequency range for the oscillator circuit is betweenkilohertz and 10 megahertz since in this frequency band it is easy toarrange for there to be a negligible component of radiated energy.

The on period can beas long as a fraction of a second (e.g. 0.1 second)or as short as a few tens of microseconds, the only requirement beingthat the burst of oscillation should be sufficiently long to enable itto be reliably detected by the detector unit. By utilising a large dutyratio, it is possible to employ an oscillator operating at a carrierfrequency as high as 10 megahertz (where a significant proportion of theenergy will produce an induction field from a coil of only a fewmillimeters in diameter) and have a mean radiated power output of theorder of microwatts.

Preferably the transmitting coil is wound into a short cylinder and ispositioned in the spherical mass of resin so that a median plane of thecoil normal to the axis of the coil lies in a diametric plane of thespherical mass. A cylindrical mercury cell makes a suitable battery andthis may be positioned so that the axis of the coil is normal to theaxis of the battery, the other component parts of the oscillator circuitbeing disposed on either side of the battery to lie within thetransmitting coil.

. The oscillator circuit may operate in the same manner from the timethe circuit is completed until the battery is finally spent (it is notdifficult to arrange for a lifetime of several years usingconventionally available batteries) but a modified oscillator circuitcan be used which can be switched on and off before and after playing around of golf. With this latter arrangement it is possible to increasethe strength of the induction field and still obtain acceptably longlifetimes for the battery.

Embodiments of golf balls in accordance with the invention will now bedescribed, by way of example, with reference to the accompanyingdrawings, in which:

FIG. 1 is a partially sectioned golf ball,

FIG. 2 is a perspective view of the spherical mass within the centre ofthe golf ball shown on an enlarged scale,

FIG. 3 is one form of circuit suitable for employment in the golf ballof FIG. 1, and

FIGS. 4 and 5 are two alternative forms of circuit.

Referring to FIGS. 1 and 2, the golf ball shown in the drawing comprisesan outer casing 1, a wound mass of elastic filament 2 and a central core3. In a normal golf ball the core 3 is a sphere of rubber with a liquidcentre. In a golf ball in accordance with the invention the rubber core3 contains a spherical recess 4 in which is located a spherical mass 5.

The mass 5 is of hard set resin material (catalytically hardened resin)of a diameter of 0.625 inch (15.9 mm) which with its electric componentsweighs 3.5 grammes. The outside diameter of the core 3 is 1.00 inch(25.4 mm), the core 3 being divided along a diametric plane to allow themass 5 to be located within the recess 4 before the core 3 isincorporated in the mass 2 and casing 1 in a manner wholly conventionalin the production of golf balls.

No alteration whatever is necessary in the components l and 2 shown inthe drawings but the core 3, as well as having a solid centre ratherthan a liquid-filled centre, is fabricated from a softer rubber thannormal, the hysteresis of the rubber being chosen so that the ballcontaining the mass 5 behaves in a similar manner to a ball' having aliquid-filled centre.

A simple circuit for incorporation in the mass 5 is shown in FIG. 3 andincludes a transistor T (a Texas Instrument 2N3708), a battery B (amercury cell) a resistor R (560K ohms), two capacitors C1 (1,500 p8) andC2 (0.1 p. F) and an intermediate-tapped coil L. The circuit componentscause oscillation at a frequency determined by the natural frequency ofthe resonant circuit C1 L at a duty ratio determined by the componentsC2 and R. The coil L has a turns ratio 4:1 and is formed into a shortcylindrical coil of diameter 0.60 rhtl-pfl lr,

The relative post spherical mass 5 is important to ensure that thecentre of gravity of the components is roughly at the centre of thespherical mass.

The components shown within the dotted line in FIG. 3 can be combined inan integrated circuit, to which are added the coil L, the battery B andthe capacitor C2.

The circuit shown in FIG. 3 operates in the same manner from the momentof its completion to the moment the battery has run down. This meansthat in tioning arise" components in the i order to ensure a life ofseveral years, the average power output must be exceedingly low and inturn this means either a limited range at which a simple radio receiverwill detect the induction field or the use of a highly sensitivedetector unit. FIGS. 4 and show alternative circuits which althoughsomewhat more complicated in their design do have the advantage of beingable to be switched on and off so that higher means power outputs areobtainable during the on periods whilst still providing a useful workinglife from a small mercury-cell.

Referring to FIG. 4, under quiescent conditions the base of a transistorT2 is connected to its emitter via a resistor R2 so there is nocollector current flowing, other than the negligibly small reversecurrent of the collector-base diode, hence there is no bias current toremove the transistor T1 from its cut-off condition. Also, the voltagedeveloped across the dc. collector load of the transistor T2 (V,') isapproximately zero.

The tapped resonant circuit in the collector of the transistor T1resonates at a frequencyfi 1/2 11' V LC3 wher e L is the totalinductance of the two primary sections of the coil, P1 and P2. If thegolf ball is placed temporarily in the magnetic induction field of anexternal exciting coil fed from an oscillating source of frequency f anoscillating voltage will appear across the resonant circuit inductanceP] P2 and a smaller voltage will appear across the secondary S. If thesecondary voltage is large enough, it will turn the transistor T1 ONinto a Class C mode of operation, the necessary negative voltage acrossthe capacitor C4 being developed by the rectifying action of thebase-emitter diode of the transistor T1. (The maximum peak-to-peakamplitude of the oscillation is limited to twice the battery voltageacross the coil P1, and to about 9 volts across the secondary S, the 9volts being the usual BE Zener breakdown voltage of most silicontransistors, and the lowest value of the voltage on the capacitor C4 isabout half the 9 volts.) However, due to the large feedback ratio S/Pl,and due to the fact that the time constant R1C4 of the base circuit ismuch larger than the oscillation period, the oscillator will start tosqueg immediately, thereby turning itself 05. The next burst ofoscillation (in the absence of the external exciter) will occur when thevoltage on the capacitor C4 is charged to about 0.6 volts through theresistor R1, but this can happen only when V* is large than 0.6 volts.

On the first turning on of the oscillator, the transient decreasingvoltage on the capacitor C4 will pull down the base voltage of thetransistor T2 via the capacitor C6, and this capacitor will supply abase current pulse if the transient voltage step exceeds 0.6 volts. Thebase current pulse, amplified by the current gain of the transistor T2,charges up the capacitor C5 to a voltage V* near the battery voltage.Hence the continual turningon of the transistor T1 after the initialswitch-on is assured.

If the exciter voltage is kept on for a time longer than necessary forstart-up, the oscillator will start its successive bursts even beforethe voltage on the capacitor C4 exceeds 0.6 volts. Hence the transientstep is reduced, and if it is reduced below a certain critical level itis not capable of driving the transistor T2 and V* drops to a negativevalue (approximately 4 volts). On the sudden removal of the excitervoltage the oscillator will not be able to start again and the golf balltherefore will be switched OFF.

Switching ON or OFF therefore uses the same exciter, which could be apart of the radio receiver used as the detector and could be activatedby a push-button switch. The exciter could even be the ferrite aerialcoil of the receiver, connected as an oscillator while the push-buttonis depressed. The actual ON or OFF operation would then be as follows:

Ball brought near (not too near) exciter and slowly removed SWITCH ONBall brought very near the exciter and quickly removed SWITCH OFF FIG. 5shows an alternative version of circuit. In this Figure a capacitor C7stores the bias voltage for a transistor T3 which is charged up via adiode D. Squegging occurs with a time constant R3 C8 and bias currentflows out of the capacitor C7 through the resistor R3. Switching ON andOFF is done with an exciter as before. On switching ON the capacitor C7charges up to 4% volts during the first rf burst. On switching OFF, asthe pulse repetition rate is increased, more current is drawn from thesmoothed supply and the supply voltage V, is reduced, thereby reducingthe oscillating voltage on P1 and therefore on S, which in turn does notkeep V* at its previous high value of 4% volts, and the oscillator stopswithout the help from the external exciter.

In the circuit of FIG. 5, C9 must be a large capacitor, while in thecircuit of FIG. 4 the values of the capacitors are small, enabling thecircuit shown in FIG. 4 to be produced in Integrated Circuit form.

The circuit shown in FIG. 4 would conveniently employ components asshown in the following Table:

TABLE B 1.4 volts P1 8 turns P2 turns S 30 turns C3 3,000 pF C4 1,000pFC6 200pF R1 1,000k R2 100k T1 n.p.n T2 p.n.p

The circuits shown in FIGS. 4 and 5 can be potted in a spherical mass ofset resin in a similar manner to that employed with the circuit of FIG.2, the component parts being positioned to give a centre of gravity asclose to the centre of the mass 5 as possible.

The circuit of FIG. 5 can be modified by placing the coil S, the diode Dand the resistor R4 in series with the emitter of the transistor T3 andconnecting the resistor R3 and the capacitor C8 to the base line.

What is claimed is:

l. A golf ball comprising an outer spherical casing; an elasticspherical mass inwardly of said outer spherical casing; and squeggingoscillator means accommodated with said elastic spherical mass andincluding an inductor serving as a transmitting coil, said oscillatormeans being operative for intermittently generating an oscillatingmagnetic field for periods of time which are shorter than the periods oftime during which said field is not generated.

2. A golf ball as defined in claim 1, wherein said squegging oscillatormeans comprises a source of electrical energy.

3. A golf ball as defined in claim 2, wherein said source of electricalenergy is a mercury cell.

4. A golf ball as defined in claim 1, and further including a resilientspherical central core inwardly of said eleastic sherical mass andhaving an internal spherical cavity, and further including a sphericalmass of set resin material inwardly of said central core and tightlyfitted within said cavity, said squegging oscillator means beingembedded within said spherical mass of set resin material.

5. A golf ball as defined in claim 4, in which said transmitting coil iswound in the form of a cylinder and positioned in said spherical mass ofresin material so that a median plane of said coil normal to the axis ofsaid coil lies in a diametric plane of said spherical mass of resinmaterial.

6. A golf ball as defined in claim 5, in which said squegging oscillatormeans comprises a mercury cell having a central axis of symmetry andserving for the supply of electrical energy and positioned in saidspherical mass of resin material and inside said coil so that the axisof said coil is normal to the axis of said mercury cell, and whereinsaid squegging oscillator means includes a plurality of other electricalcomponents located to either side of said mercury cell and also locatedwithin said coil.

7. A golf ball as defined in claim 1, wherein said inductor constitutesa transmitting coil, and wherein said squegging oscillator meanscomprises a npn transistor having an emitter, a collector and a base, acapacitor connected in parallel to said transmitting coil to form aparallel LC circuit having a predetermined resonance frequency, and abattery connected between an intermediate tap of said coil and saidemitter, a parallel RC- circuit connected to said base, the ends of saidparallel circuits not connected to said transistor being connectedtogether and the resonant frequency of the RC circuit being a fractionof said predetermined resonance frequency.

8. A golf ball as defined in claim 1, wherein said squegging oscillatormeans includes magnetic-field responsive means operative for terminatingoperation of said oscillator means when the golf ball is brought intoand then moved out of an AC. magnetic field.

9. A golf ball as defined in claim 1, and wherein said squeggingoscillator means includes magnetic-fieldresponsive means operative forterminating operation of said squegging oscillator means when the golfball is brought into and then moved out of an AC. magnetic field havinga predetermined frequency.

1. A golf ball comprising an outer spherical casing; an elasticspherical mass inwardly of said outer spherical casing; and squeggingoscillator means accommodated within said elastic spherical mass andincluding an inductor serving as a transmitting coil, said oscillatormeans being operative for intermittently generating an oscillatingelectromagnetic field for periods of time which are shorter than theperiods of time during which said field is not generated.
 2. A golf ballas defined in claim 1, wherein said squegging oscillator means comprisesa source of electrical energy.
 3. A golf ball as defined in claim 2,wherein said source of electrical energy is a mercury cell.
 4. A golfball as defined in claim 1, and further including a resilient sphericalcentral core inwardly of said eleastic spherical mass and having aninternal spherical cavity, and further including a spherical mass of setresin material inwardly of said central core and tightly fitted withinsaid cavity, said squegging oscillator means being embedded within saidspherical mass of set resin material.
 5. A golf ball as defined in claim4, in which said transmitting coil is wound in the form of a cylinderand positioned in said spherical mass of resin material so that a medianplane of said coil normal to the axis of said coil lies in a diametricplane of said spherical mAss of resin material.
 6. A golf ball asdefined in claim 5, in which said squegging oscillator means comprises amercury cell having a central axis of symmetry and serving for thesupply of electrical energy and positioned in said spherical mass ofresin material and inside said coil so that the axis of said coil isnormal to the axis of said mercury cell, and wherein said squeggingoscillator means includes a plurality of other electrical componentslocated to either side of said mercury cell and also located within saidcoil.
 7. A golf ball as defined in claim 1, wherein said inductorconstitutes a transmitting coil, and wherein said squegging oscillatormeans comprises a npn transistor having an emitter, a collector and abase, a capacitor connected in parallel to said transmitting coil toform a parallel LC circuit having a predetermined resonance frequency,and a battery connected between an intermediate tap of said coil andsaid emitter, a parallel RC-circuit connected to said base, the ends ofsaid parallel circuits not connected to said transistor being connectedtogether and the resonant frequency of the RC circuit being a fractionof said predetermined resonance frequency.
 8. A golf ball as defined inclaim 1, wherein said squegging oscillator means includes magnetic-fieldresponsive means operative for terminating operation of said oscillatormeans when the golf ball is brought into and then moved out of an A.C.magnetic field.
 9. A golf ball as defined in claim 1, and wherein saidsquegging oscillator means includes magnetic-field-responsive meansoperative for terminating operation of said squegging oscillator meanswhen the golf ball is brought into and then moved out of an A.C.magnetic field having a predetermined frequency.